A Guide to Baby Poop, Pee and Spit Up

What goes in must come out, and in the world of babies that fact takes on a whole new meaning. It will seem like your baby pees, poops and spits up way more than he takes in, leaving you wondering if he’s getting any nourishment at all. To reassure yourself that he is not going to wither and die from malnutrition anytime soon, you will find that you inspect diaper contents with a zeal once reserved for an elegant gourmet dinner, then discuss them ad nauseam with your partner, relatives, friends and strangers in the grocery checkout line. Anyone who has ever been a parent will relish the conversation, fully sympathizing with where you’re coming from. (Anyone who has never had this privilege will find you revolting, but who needs them right now anyway?) Meanwhile, there are really only a few things you need to get straight.

Pees and q’s.

First off, it’s going to take a few days to jump start your baby’s system. If you’re breastfeeding, it may not be until your milk fully comes in (between two and five days) that she starts to wet the expected eight to ten diapers a day. The hospital staff will be keeping an eye on her production while you’re in there, but when you get home five or so wet diapers may be the norm for two or three days; then she’ll up the ante. If your baby’s urine output doesn’t seem to increase, check with your pediatrician ASAP.

In this era of super-absorbent disposable diapers, it can be tricky to tell if they’re actually wet. Our best advice is to familiarize yourself with the texture of the diaper layers when they’re dry, then touch them to see if they feel a bit puffier at the next change. The gels inside inflate as they absorb the urine. This will also make the diaper feel heavier. Still uncertain? Go ahead and give the diaper a sniff at the front leg area and see if you get a whiff of that unmistakable urine smell. (You’ll be doing a lot more gross stuff than this as time goes on.) Once you’ve started changing her, if you still can’t be sure there’s pee in it, put the diaper back on and wait another hour or so, then check again.

Poop parameters.

You’ve no doubt heard that breastfed babies poop messy, runny, French’s-mustard-colored stools at every feeding, but again, this becomes true only after about the first week. Immediately postpartum, babies produce a thick, black tar-like poop called meconium (this may happen in the hospital, so you may not see it). Then as breast milk and/or formula begin to make their way through the system, the stools become brown and pasty. Formula-fed babies will continue to poop this way (though it becomes more formed, and the color may vary), while breastfed babies will go on to the thinner, yellow, seedy variety of legend.

The next fun feature about baby poop you’ll find yourself obsessing over is how often to expect it. Again, many breastfed babies have a bowel movement during or after almost every feeding. However, this truism does not apply to all. Formula-fed babies are definitely less frequent poopers, and may even go as little as every few days. This behavior usually sends grandparents into a total panic, and by default new parents as well. Because babies are also notoriously loud poopers—straining, grunting and getting very red-faced—all of this can add up to major anxiety about the big C: constipation. Try to tune Grandma out on this one: Babies are seldom constipated. Like adults, infants are unique in their bowel habits, and your pediatrician is likely to dismiss your concerns. As long as the poop is soft when it eventually arrives, your baby will be diagnosed as quite normal.

Another related myth along these same lines pertains to the iron content in formula. As you yourself may have experienced very recently, iron supplements can be, well, binding in adults. Not so with babies, and don’t be tempted by low-iron formulas (which most medical experts think should be pulled from the market). Full-iron formulas are essential for your baby’s brain development and will not constipate him. Nor will the iron supplements your pediatrician prescribes for your baby if he’s being breastfed. Don’t let anyone tell you otherwise.

Spit happenings.

The mouth, of course, is at the other end of the bodily fluid spectrum, and many babies spit up as often as ten or twelve times a day. Sometimes we’re talking a major eruption; other times it just trickles out like overflow. Either way it’s messy. One mom told us that whenever she was trying to get ready to go somewhere with her firstborn, she could never decide whether to dress herself first, then have her daughter spit up on her, or dress her daughter first and watch her spit up on herself. No matter how much experts describe spit-up as just a nuisance, it’s these little issues that make moms go bonkers.

As for the science behind it, if you must know, the most common reason for spitting up is that a baby’s digestive tract muscle between the stomach and the esophagus is immature (essentially, it’s loose and will gradually tighten up by about six months of age). Most babies are not bothered by spitting up, and there’s probably a lot less nutrition being lost than you think—typically about a tablespoon, but because the breast milk or formula mixes with other fluids, it can seem like more. Just keep plenty of bibs, towels and clothes for quick cleanups on hand, especially when you go out. (Keeping an extra change of clothes for yourself in your trunk isn’t a bad idea, either.)

To minimize spitting up, try these tactics:

Keep feedings smaller and more frequent.

Don’t pressure your baby to finish a feeding if he seems full.

Hold or keep your baby sitting upright after feedings for a little while to let gravity help with digestion.

Burp your baby regularly.

If you’re feeding your baby formula, talk to your pediatrician about a brand that might be easier for him to digest.

Occasionally, spitting up warrants medical attention. If your baby is very irritable and fussy and prone to spitting up, he may have a reflux problem that could be relieved with medication. If your baby experiences true vomiting—more forceful expelling of a greater amount of his stomach contents—diarrhea, bloating and is not gaining weight adequately, he may have a milk allergy, so discuss it with your doctor. Both reflux and milk allergies are uncommon, but they do occur. Spitting up any blood is a sign of infection, and yellowish green bile indicates a blockage, so if you see either of these, call your doctor right away.